Balanced to unbalanced circuit connector



H. A. WHEELER BALANCED '10 UNBALANCED CIRCUIT CONNECTOR ZAW,

Fi led June 5, 1945 2 Sheets-Sheet 1 SHURT-WAVE Q SIGNAL GENERATOR 0 7*Nu X 3d 3 (lmpadame Z $.36 PX am Ila mm-m I 7 F; g gl V l3 hnmdance 2 TA 30 3g Hmpedcnca; Z.)

I l INVENTOR 2/ no HAROLD A. WHEELER (\mpaaunce Z ATTOR NEY m T C E N No m. R w Lm "m0 H m m T MW 0 T D E c N A L A B arch 25, 1947.

Filed June 5, 1945 2 Sheets-Sheet 2 R r Y E M M M ni h V 0 N W ID Almpadunw Z Patentecl Mar. 25, 1947 BALANCED 'ro nrmnmncan CIRCUITconnnoron Harold A. Wheeler, Great NeclnN. Y, assignor, by mesneassignments, to liazeltine Research, Inc, Chicago, Ill., a corporationof Illinois Application June 5, 1945, Serial No. 597,655

15 Claims. (01. 178-44) through to a balanced circuit. A pair of thinlongitudinal slots are cut into one end of the outer conductor orshieldof the coaxial line so that the shield at the slotted endcomprises a pair of conductive portions. Usually, the slot length issuch that the pair of conductive portions individually have anelectrical length equal to onequarter of the mean operating wave lengthof the connector. The inner conductor of the coaxial line is bonded atthe end to one of the conductive portions provided in the slottedsection of the shield. With this construction, one end of the connectormay be utilized as a conventional unbalanced transmission line adaptedfor direct connection with the unbalanced circuit. At the other end ofthe connector, the two conductive portions of the shield may be utilizedas balanced terminals for connection with the balanced circuit.

The described connector is desirable from a mechanical standpoint inview of its simplicity but it has certain electrical characteristicswhich may be undesirable in particular installations. It has beendiscovered experimentally that the expedient of slotting the shieldconductor and bonding the inner conductor to one of the resulting shieldportions causes the chraracteristic impedance of the balanced circuitprovided at one end of the connector to be twice that of the unbalancedcircuit provided at the opposite end. In other words, an impedancediscontinuity is encountered at the junction of the balanced andunbalanced circuit portions of the connector. Since reflections arise atpoints of impedance discontinuity, the prior-art connector is unsuitedfor certain installations.

It is an object of the present invention, therefore, to provide abalanced-to-unbalanced circuit connector which substantially avoids theaforementioned limitationzof prior-connectors.

It .is another object 'of the invention, 'to provide an improvedbalanced-tounbalanced circuit connector having a substantially uniformcharacteristic impedance throughout its balanced and unbalanced circuitportions.

It is a specific object of the invention to provide an improvedbalanced-to-unbalanced circuit connector of the coaxial type foroperation over a wide range of wave lengths.

A balanced-to-unbalanced circuit connector in accordance with thepresent invention comprises an outer conductor including a first sectionand a contiguous second section. The second section has a pair oflongitudinal slots extending from one end of the outer conductor andforming in the second section a pair of conductive portions. Theconnector also has an inner conductor including a first section and acontiguous second section coaxially supported within the first andsecond sections, respectively, of the outer conductor. The innerconductor is connected to one of the conductive portions formed in theouter conductor substantially at the free end thereof. The firstsections of the inner andouter conductors have a, relative spacingselected to provide an unbalanced transmission line having apredetermined characteristic impedance at a given operating wave length.The second sections of the inner and outer conductors have a relativespacing selected so that the second section of the inner conductor andthe other one of the pair of conductive portions provide a balancedtransmission line having approximately the aforesaid predeterminedcharacteristic impedance.

For a better understanding of the present invention, together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawings, and itsscope will be pointed out in the appended claims.

In the drawings, Fig. 1 is a view, partially in cross section, showing acircuit connector in accordance with the present invention connecting anantenna system to a wave-signal generator; Fig. 2 is an end view of thebalanced circuit portion of the connector; Fig. 3 is a schematic circuitdiagram of the Fig. 1 connector; Figs. 3a3d,

inclusive, are used in assimilating the individual circuit portions ofFig. 3 with the mechanical connector arrangement of Fig. 1; Fig. 4 is anend view of the balanced-circuit portion of a modified connector of thetype of Fig. 1; Fig. 5 is a similar end view of a, further modification0f the Fig. 1 arrangement; Fig. 6 represents another embodiment of theinvention; Fig. 7 is an end view of the balanced-circuit portion of theFig. 6 concular in cross section. Each conductor includes a first secton and a contiguous second section, the first sections being onlypartially shown and the second sect-ions having a length designated bydimension line L. More particularly, the outer conductor has a groundedfirst section II) which may have any length desired in accordance withthe intended use of the connector. For this reason only a portion ofthis section is illustrated. The second section of the outer conductoris designated Ila, IIb and, in a preferred embodiment of the invention,has a length L approximately equal to one-quarter of the mean operatingwave length of the connector. This second section of the outerconductor, as shown in Fig. 2, has a pair of diametrically opposed, thinlongitudinal slots I4 and I5 extending throughout the entire length ofthe second section. These slots form in the second section of the outerconductorthe pair of conductive portions Ila and III), which mayindividually have an electrical length equal to onequarter of the meanoperating wave length.

The first and second sections of the inner conductor are designated I2and I3, respectively. They are coaxially supported, by means of suitableinsulating spacers IE, IS, within the first and second sections,respectively, of the outer conductor. The inner conductor is connectedto one of the conductive portions formed in the second section of theouter conductor. For this purpose, the free end of inner-conductorsection I3 is supported by a semi-circular conductive member I1 which issoldered, welded, or otherwise conductively connected to and supportedby the free end of portion Ilb of the outer conductor.

The first sections I ll and I2 of the inner and outer conductors have arelative spacing selected to provide an unbalanced transmission linehaving a predetermined characteristic impedance at the mean operatingwave length. This unbalanced transmission line may be directly connectedwith a signal-translating arrangement, such as the short-wave signalgenerator 20 having an unbalanced output circuit. The second sectionsIla, IIb and I3 of the inner and outer conductors have a relativespacing selected so that the second section I 3 of the inner conductorand conductive portion Ila of the outer conductor provide a balancedtransmission line, having approximaely the same characteristic impedanceat the mean operating'wave length as the unbalanced line provided bysections III and I2. The balanced transmission line is directlyconnected with a dipole antenna consisting of a pair of radiatingelements 25 and 2B, individually having an efiective electrical lengthequal to onequarter of the mean operating wave length. Radiating element25 is directly connected with conductive portion Ila of the balancedtransmission line, while the alternate radiating element 26 is connectedwith the remaining conductor l3 of the balanced line.

The electrical circuits represented by the mechanlcal structure of Fig.1 are illustrated schematically in Fig. 3. Figs. 3a to 3d, inclusive,indicate the conductive elements of the connector which are thecounterparts of the conductors of Fig. 3. The directional arrows 3a-3ato 3d-3d denote the circuit portions represented by Figs. 3a3d and theimpedance notations associated with each such figure designate thecharacteristic impedance of the particular circuti portion. In Fig. 3conductors l0 and I2 constitute an unbalanced transmission line. Asshown in Fig. 3a, this unbalanced-line portion is provided by sectionsI0 and I2 of the outer and inner conductors, respectively, of theconnector. It has a characteristic impedance Z0 determined by therelative diameters of its coaxial conductors. Assuming the outerconductor of the connector to have a uniform and preselected diameterequal to do, the diameter (11 oi inner-conductor section I2 is selectedwith reference thereto in order to obtain the desired characteristicimpedance Z0 for the unbalanced-line portion of the connector. Thisportion extends from the unbalanced input terminals of the connector towhich generator 20 is connected to the junction of the first and secondsections of the inner and outer conductors. The junction is designatedby the broken line AA in Fig. 3.

The balanced transmission-line portion of the connector starts at thejunction A-A. It is formed of the conductors Ila and I3 which, as shownin Fig. 3b, are provided by section IIa of the outer conductor andone-half of inner conductor section I3, where section I3 is bisected byan imaginary plane X-X. The plane X-X bisects the inner and outerconductors of the connector and is normal to the plane of the drawings.The balanced line Ila, l3 has a characteristic impedance Z1 determinedby the relative spacing or diameters of its conductors. The specificconductor spacing and the resulting value of the characteristicimpedance is to be particularly described hereinafter.

Electrically, the connector also embodies a pair of stub lines locatedat the opposite terminal portions of the balanced-line portion Ila, l3.The first such stub line, coupled to the balancedline portion atjunction A-A, includes conductors Ill) and I3". As shown in Fig. 30,these conductors are provided b outer conductor section IIb and one-halfof inner conductor section I3. Since member I! bonds the ends of theseconductors together, as indicated at 11', the first stub line Ilb', I3"is a short-circuited line section. It has a characteristic impedance Z1which is equal to that of the balanced-line portion I la, I3 since, inthe Fig. 1 arrangement, the conductors of these two line sections areidentical in construction and spacing.

The second stub line, located at the free end of the balanced-lineportion Ila, I3 includes conductors Ila" and Ilb". As shown in Fig. 3d,these conductors are provided by the conductive portions Ila and I lbformed in the outer conductor by slots III and I5. Since the conductiveportions I la and ill) are joined at the closed ends of slots I4 and I5,the second stub line Ila", Ilb" is also a short-circuited line section.It has a characteristic impedance Z: which may be controlled byvariations in the width of slots I4 and I5. This impedance Z2 may beconsidered as the balanced characteristic impedance of the outerconductor, that is, the impedance of the slots and the outside of theslotted section of the outer conductor. This second stub line representsnecessary to establish a uniform characteristic impedance between thebalanced and unbalanced-line portions of the connector may readily bedetermined. It becomes apparent immediately that the impedance Z1 of thebalancedline ortion IIa, I3 must be approximately equal to thecharacteristic impedance Z of the unbalanced-line portion III, I2. Thisresult is obtained by appropriately selecting the diameter (12 ofinner-conductor section I3 with reference to the diameter do of theouter conductor. In the Fig. 1 embodiment the same dielectric material(air) fills the inter-conductor space in the balanced andunbalanced-circuit portions of the connector. For this reason, thebalanced and unbalanced-line portions have equal characteristicimpedances, as required, by selecting the diameter d2 of inner-conductorsection I3 to be equal to the geometric mean of the diameters do and d1of conductor sections Ill and I2, respectively. By thus selecting thespacing of the first sections of the inner and outer conductors as wellas the spacing of the second sections of these conductors, the balancedand unbalanced-line portionsof the connector represent a uniformcharacteristic impedance. Where this impedance equals the unbalancedterminal impedance of generator 20 and the balanced terminal impedanceof dipole antenna 25, 26, maximum power transfer between the generatorand the antenna results. Before considering the wide-band operatingcharacteristics of the connector of Fig. 1, it is expedient to view theimpedance relationships of its balanced and unbalanced-line portionsfrom a slightly different viewpoint.

It has been stated with reference to Figs. 3 and 3a that theunbalanced-line portion ID, I2 has a characteristic impedance Z0 and isprovided by conductor sections ii) and I2. Since section I0 is groundedand constitutes a sheath enclosing section I2, the unbalanced-lineportion may be viewed as comprising a pair of unbalanced lines connectedin parallel and individually having a characteristic impedanceequal to2Z0. One of this pair of lines consists of one-half of each ofconductorsections In and I2, while the other is provided by the remaining halvesof these sections, and the imaginary plane X-X designates the meetingplane of the two lines. Therefore, if the contiguous second sections ofthe inner and outer conductors which provide the balanced-line portionI-Ia', I3 of the connector have the same diameters and dielectricloading as their first sections, an impedance discontinuity is caused atthe junction AA. The discontinuity arises because the balanced-lineportion Ila, I3, assuming the inner and outer conductors of theconnector to have uniform diameters and dielectric loading, is formed ofconductors having the same spacing as the conductors of each of the pairof parallel-connected unbalanced lines eiiective- 1y included inunbalanced portion I0, I 2' and consequently its characteristicimpedance Z1 is equal to 220. In other words, where the inner and outerconductors of the connector have uniform diameters and a homogeneousdielectric therebetween, such as air, the unbalanced-line portion I0,I2'- has an impedance Z0 and the balanced-line portion Ila, I3 has animped- 6 ance of twice that value. This discontinuity is encountered inthe prior connectors referred to above but is avoided in the Fig. 1embodiment by enlarging the diameter of inner conductor Hit The changein diameter is selected so that the characteristic impedance Z1 orthe.balanced-line portion is approximately equal to that of theunbalanced-line portion.

For optimum operation over a wide range of wave lengths, the matchedimpedance relation between the balanced and unbalanced-line portions ofthe connector is established at the mean operating wave length. Also,the slots I4 and I5 have a length L equal to one-quarter of the meanwave length. Where these conditions are satisfled, each of the stublines IIb', I3" and Ila",

III)" represents a short-circuited quarter-wave line. At the meanoperating wave length each line is then equivalent to an infiniteimpedance or an open circuit. I The first stub line No,

I3 has the same characteristic impedance Zi as the balanced-line portionIla, I3. optimum wide-band operation, line IIa, IIb" should have anequal characteristic impedance.- This is obtained by appropriatelyselecting the width of slots Id and I5. With quarter-waveshort-circuited stub lines individually having a characteristicimpedance substantially equal to that of the balanced-line portion ofthe connector, optimum wide-band operation results since. the impedancevariations of the stub lines cancel one another at the operating wavelengths of the desired range.

In certain applications, the connector may be constructed to compensatefor impedance variations of the balanced-circuit arrangement For thesecond stub coupled thereto. Consider, for example, the case I in whichthe balanced dipole antenna 25, 26 is series-resonant at the mean wavelength of the operating band. The impedance of the antenna is,therefore, a minimum at the mean Wave length and increases with wavelength variations in either direction therefrom. To compensate for suchimpedance variations of the antenna, loading means may be providedadjacent to the conductive portions Ila and Nb of the outer conductorfor appropriately determining the characteristic impedance Z2 of thesecond stub line. Such a modification of the connector is represented inFig. 4 which is an end view of the balanced-line portion. Asillustrated, horizontally disposed flange members 2i, 2| extend from andalong the length of conductive portion II a. Similar flange members 22,22 extend along conductive portion IIb. These flanges increase thedistributed capacitance between portions I Ia, I Ib and decrease theinductane thereof to decrease the characteristic impedance Z2 of thesecond stub line. As a consequence, the characteristic impedances of thefirst and second stub lines are diiferent, the impedance of the secondline being selected to compensate for impedance variations of the firststub line as well as the dipole antenna 25, 26. More specifically, thecharacteristic impedance of the seconds'tub line Ila", IIb" is less thanthat of the first stub line Iib', I3 by an amount eflective to providethe-desired impedance compensation.

In Fig. 5 there is represented an end viewof the balanced-line sectionof a further modification of the Fig. 1 connector. The Fig.5 embodimentis generally similar to that of Fig. 4, difiering only in the manner. ofloading the second stub line for improved wide-band operation in view ofa. particular balanced-circuit. arrangement In the instant case thesecond stub line Ila", I Ib" is decreased bya first conductive element23 extending along the length of conductive portion I la and curvedaround the alternate portion I lb. A similar conductive element 24projects from portion IIb and extends around portion I Ia. Elements 23and 24 are proportioned to determine the characteristic impedance of thesecond stub line as required to effect the desired impedancecompensation.

In the embodiments of Figs. 4 and 5 where the second stub line isconstructed to compensate for impedance variations introduced by thebalancedcircuit arrangement coupled to the connector, consideration wasgiven to the case in which the balanced circuit is series-resonant atthe mean operating wave length. For the alternate type of balancedcircuit which is parallel-resonant at the mean wave length, a likeimpedance compensation may be achieved by constructing or loading thesecond stub line Ila", III)" to have a characteristic impedance which isgreater than that of the first stub line I Ib, I3".

For some purposes, it may be desired to arrange the connector so thatits first stub line I II), I3" has a high characteristic impedance. Sucha construction is represented in Figs. 6 and 'Z. The connector isgenerally similar to that of Fig. 1 and corresponding components thereofare identified by like reference characters. In this embodiment, thesecond section I3 of the inner conductor has a hollow semi-circularcross section. The schematic circuit diagram of Fig. 3 also representsthe electrical circuits included in the connector of Figs. 6 and 7.Likewise, the

views of Figs. 3a, 3b and 3d and the impedance notations associatedtherewith illustrate the counterparts of the electrical portions of Fig.3 found in the mechanical construction of Fig. 6. The first stub line Ilb, l3" of Fig. 3 is provided by the conductive portion Nb of the outerconductor and inner-conductor section I3 as shown in Fig. 8. Theseconductors have an impedance Z3, determined by their relative spacing,which is substantially greater than that of the balancedline portionIla, I3.

In describing the illustrated circuit connectors, the diameters of thefirst and second sections of the inner and outer conductors have beensaid to be proportioned so that the balanced and unbalanced-lineportions of the connector have substantially the same characteristicimpedance. It will be understood that the relative diameters of theconductor sections establish the inter-ccnductor spacing and theimpedance of the transmission lines. The spacing is always selected inview of the dielectric as well as the magnetic properties of theinter-conductor space and the region immediately outside the outerconductor. Where the coaxial conductors have anair separation, thespacing has a given value in order to obtain a desired impedance level.If some other substance having difierent dielectric and magneticproperties fills the space betwen the conductors, the spacing usuallyhas a different value to establish the same impedance level for theline. The term "relative spacing" and similar expressions of theappended claims designate the conductor spacing in view of the linedielectric and similar factors. The balanced-line portion of the circuitconnector may, if desired, have a different material in theinter-conductor space than the unbalancedline section. Where thematerials filling the interconductcr spaces of the balanced andunbalanced-circuit portions have the proper relative dielectric andmagnetic characteristics, each of the inner and outer conductors of theconnector may have a uniform diameter while obtaining the desiredimpedance relationships.

Slots I I and I5 of the outer conductor are usually thin. That is, theslot width in practical cases is less than the radial clearance betweenthe inner and outer conductors of the connectors.

While there have been described what are at present onsidered to be thepreferred embodiments of this invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is, therefore,aimed in the appended claims to cover all such changes and modificationsas fall within the true spirit and scope of the invention.

What is claimed is:

l. A balanced-to-unbalanced circuit connector comprising, an outerconductor includin a first section and a contiguous second sectionhaving a pair of longitudinal slots extending from one end of said outerconductor and forming in said second section a pair of conductiveportions, an inner conductor including a first section and a contiguoussecond section coaxially supported within said first and second sectionsrespectively of said outer conductor and connected to one of saidconductive portions substantially at the free end thereof, said firstsections of said inner and outer conductors having a relative spacingselected to provide an unbalanced transmission line having apredetermined characteristic impedance at a given operating wave length,and said second sections of said inner and outer conductors having arelative spacing selected so that said second section of said innerconductor and the other one of said pair of conductive portions providea balanced transmission line having approximately said predeterminedcharacteristic impedance.

2. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a contiguous second section of apredetermined length having a pair of longitudinal slots extending fromone end of said outer conductor andforming in said second section a pairof conductive portions, an inner conductor including a first section anda contiguous second section of said predetermined length coaxiallysupported within said first and second sections respectively of saidouter conductor and connected to the free end of one of said conductiveportions, said first sections of said inner and outer conductors havinga relative spacing selected to provide an unbalanced transmission linehaving a predetermined characteristic impedance at a given operatingwave length, and said second sections of said inner and outer conductorshaving a relative spacing selected so that said second section of saidinner conductor and the other one of said pair of conductive portionsprc vide a balanced transmission line having approximately saidpredetermined characteristic impedance.

3. A balanced-to-unbalanced circuit connector comprising, an outercylindrical conductor including a first section and a contiguous secondsection having a pair of longitudinal slots extending from one end ofsaid outer conductor and forming in said second section a. pair ofconductive portions, an inner cylindrical conductor including a firstsection and a contiguous second section ccaxially supported within saidfirst and second sections respectively of said outer conductor andconnected to one of said conductive portions substantially at the freeend thereof, said first sections of said inner and outer conductorshaving relative diameters selected to provide an unbalanced transmissionline having a predetermined characteristic impedance at a, givenoperating wave length, and said second sections of said inner and outerconductors having relative diameters selected so that said secondsection of said inner conductor and the other one of said pair ofconductive portions provide a balanced transmission line havingapproximately said predetermined characteristic impedance.

4. A balanced-to-unbalanced circuit connector comprising, an outercylindrical conductor of substantially uniform diameter including afirst section and a contiguous second section having a pair oflongitudinal slots extending from one end of said outer conductor andforming in said second section a pair of conductive portions, an innercylindrical conductor including a first section and a contiguous secondsection coaxially supported within said first and second sectionsrespectively of said outer conductor and connected to one of saidconductive portions substantially at the free end thereof, said firstsection of said inner conductor having a diameter selected withreference to the diameter of said outer conductor so that said firstsections of said inner and outer conductors provide an unbalancedtransmission line having a predetermined characteristic impedance at agiven operating wave length, said second section of said inner conductorhaving a diameter selected with reference to the diameter of said outerconductor so that said second section of said inner conductor and theother one of said pair of conductive portions provide a balancedtransmission line having approximately said predetermined characteristicimpedance.

5. A balanced-to-unbalanced circuit connector comprising, an outercylindrical conductor of circular cross section and substantiallyuniform diameter including a first section and a contiguous secondsection having a pair of longitudinal slots extending from one end ofsaid outer conductor and forming in said second section a pair ofconductive portions, an inner cylindrical conductor of circular crosssection including a first section and a contiguous second sectioncoaxially supported'within said first and second sections respectivelyof said outer conductor and separated therefrom by a homogeneousdielectric, means for connecting said inner conductor to one of saidconductive portions substantially at the free end thereof, said firstsection of said inner conductor having a diameter selected withreference to the diameter of said outer conductor so that said firstsections of said inner and outer conductors provide an unbalancedtransmission line having a predetermined characteristic impedance at agiven operating wave length, said second section of said inner conductorhaving a diameter substantlally equal to the geometric mean of thediameters of said first sections of said inner and outer conductors sothat said second section of said inner conductor and the other one ofsaid pair of conductive portions provide a balanced transmission linehaving approximately said predetermined characteristic impedance.

6. A balanced-to-unbalanced circuit connector comprising, an outercylindricalconductor or circular cross section including a first sectionand a contiguous second section having a pair of diametrically opposedlongitudinal slots extending ed to provide an unbalanced transmissionline having a predetermined characteristic impedance at a, givenoperating wave length, and said second sections of said inner and outerconductors having relative diameters selected so that said secondsection of said inner conductor and the other one of said pair ofconductive portions provide a balanced transmission line havingapproximately said predetermined characteristic impedance.

7. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a, contiguous second sectionhaving a pair of longitudinal slots extending from one end of said outerconductor and formin in said second section a pair of conductiveportions, an inner conductor including a first section and a contiguoussecond section coaxially supported within said first and second sectionsrespectively of said outer conductor, conductive means for connectingthe free end of said second section of said inner conductor to thecorresponding end of one of said conductive portions, said firstsections of said inner and outer conductors having a relative spacingselected to provide an unbalanced tranmission line having apredetermined characteristic impedance at a given operating wave length,and said second sections of said inner and outer conductors having alected so that said second section of said inner conductor and the otherone of said pair of conductive portions provide a balanced transmissionline having approximately said predetermined characteristic impedance.

8. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a contiguous second sectionhaving a pair of longitudinal slots extending from one end of said outerconductor and forming in said second section a pair of conductiveportions, and an inner conductor including a first section and acontiguous second section coaxially supported within said first andsecond sections respectively of said outer conductor, conductive meansfor supporting and for connecting the free end of said second section ofsaid inner conductor to the corresponding end of one of said conductiveportions, said first sections of said inner and outer I conductorshaving a relative spacing selected to provide an unbalanced transmissionline, having a predetermined characteristic impedance at a givenoperating wave length, and said .second sections of said inner and outerconductors having a relative spacing selected so that said secondsection of said inner conductor and the other one of said pair ofconductive portions provide a balanced transmission line havingapproximately said predetermined characteristic impedance.

9. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a contiguous secondsectionhaving a pair of longitudinal slots extending from one end of said outerconductor and forming in said second section a pair of conductiveportions individually having an eirective electrical length aprelativespacing seproximately equal to one-quarter of a given operating wavelength, an inner conductor including a first section and a, contiguoussecond section coaxially supported within said first and second sectionsrespectively of said outer conductor, said second section of said innerconductor having an efiective electrical length approximately equal toone-quarter of said wave length and being connected to One of saidconductive portions substantially at the free end thereof, said firstsections of said inner and outer conductors having a relative spacingselected to provide an unbalanced transmission line having apredetermined characteristic impedance at Said wave length, and saidsecond sections of said inner and outer conductors having a relativespacing selected so that said second section of said inner conductor andthe other one of said pair of conductive portions provide a balancedtransmission line having approximately said predetermined characteristicimpedance.

10. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a contiguous second sectionhaving a pair of longitudinal slots extending from one end of said outerconductor and forming in said second section a pair of conductiveportions individually having an effective electrical length equal toone-quarter of a given operating wave length, means adjacent to saidconductive portions for determining the characteristic impedancetherebetween, an inner conductor including a first section and acontiguous second section having an effective electrical length equal toone-quarter of said wave length coaxially supported within said firstand second sections respectively of said outer conductor and connectedto one of said conductive portions substantially at the free andthereof, said first sections of said inner and outer conductors having arelative spacing selected to provide an unbalanced transmission linehaving a predetermined characteristic impedance at said wave length, andsaid second sections of said inner and outer conductors having arelative spacing selected so that said second section of said innerconductor and the other one of said pair of conductive portions providea balanced transmission line having approximately said predeterminedcharacteristic impedance.

11. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a'contiguous second sectionhaving a pair of longitudinal slots extending from one end of said outerconductor and forming in said second section a pair of conductiveportions individually having an effective electrical length equal toone-quarter of a given operating wave length, flange members extendingfrom said conductive portions along the length of said slots fordecreasing the characteristic impedance therebetween, an inner conductorincluding a first section and a contiguous second section having aneffective electrical length equal to onequarter of said wave lengthcoaxially supported within said first and second sections respectivelyof said outer conductor and connected to one of said conductive portionssubstantially at the free end thereof, said first sections of said innerand outer conductors having a relative spacing selected to provide anunbalanced transmission line having a. predetermined characteristicimpedance at said wave length, and said second sections of said innerand outer conductors having a relative spacing selected so that saidsecond section of said inner conductor and the other one of said pair ofconductive portions provide a balanced transmission line havingapproximately said predetermined characteristic impedance. A

12. A balanced-to-unbalanced circuit connector for operation over a widerange of wave lengths comprising, an outer conductor including a firstsection and a contiguous second section having a pair of longitudinalslots extending from one end of said outer conductor and forming in saidsecond section a pair of conductive portions individually having aneffective electrical length approximately equal to one-quarter of themean wave length of said range, an inner conductor including a firstsection and a contiguous second section coaxially supported within saidfirst and second sections respectively of said outer conductor, saidsecond section of said inner conductor having an effective electricallength approximately equal to one-quarter of said mean wave length andbeing connected to one of said conductive portions substantially at thefree end thereof, said first sections of said inner and outer conductorshaving a relative spacing selected to provide an unbalanced transmissionline having a predetermined characteristic impedance at said mean wavelength, said second sections of said inner and outer conductors having arelative spacing selected so that said second section of said innerconductor and the other one of said pair of conductive portions providea balanced transmission line having approximately said predeterminedcharacteristic impedance, and said slots having such width that saidconductive portions of said outer conductor provide a stub line having acharacteristic impedance substantially equal to that of an additionalstub line formed by said second section of said inner conductor and saidone conductive portion of said outer conductor.

13. A balanced-to-unbalanced circuit connector for operation over a widerange of wave lengths and for connection with a balanced circuitarrangement which is resonant at the mean wave length of said rangecomprising, an outer conance therebetween, an inner conductor includinga first section and a contiguous second section coaxially supportedwithin said first and second sections respectively of said outerconductor, said second section of said inner conductor having aneffective electrical length approximately equal to one-quarter of saidmean wave length and being connected to one of said conductive portionssubstantially at the free end thereof, said first sections of said innerand outer conductors having a relative spacing selected to provide anunbalanced transmission line having a predetermined characteristicimpedance at said mean wave length, said second sections or said innerand outer conductors having a relative spacing selected so that saidsecond section of said inner conductor and the other one of said pair ofconductive portions provide a balanced transmission line havingapproximately said predetermined characteristic impedance, and saidloading means being so selected that said conductive portions of saidouter conductor provide a stub line having a characteristic impedancedifferent from that of an additional stub line formed by said secondsection of said inner conductor and said one conductive portion of saidouter conductor and effective substantially to compensate the impedancevariations of said balanced circuit arrangement and said additional stubline over said range of wave lengths.

14. A balanced-to-unbalanced circuit connector for operation over a widerange of wave lengths and for connection with a balanced circuitarrangement which is series-resonant at the mean wave length of saidrange comprising, an outer conductor including a first section and acontiguous second section having a pair of longitudinal slots extendingfrom one end of said outer conductor and forming in said second sectiona pair of conductive portions individually having an efiect veelectrical length approximately equal to one-quarter of the mean wavelength of said range, loading means adjacent to said conductive portionsfor determining the characteristic impedance therebetween, an innerconductor including a, first section and a contiguous second sectioncoaxially supported within said first and second sections respectivelyof said outer conductor, said second section of said inner conductorhaving an efiective electrical length approximately equal to one-quarterof said mean wave length and being connected to one of said conductiveportions substantially at the free end thereof, said first sections ofsaid inner and outer conductors having a relative spacing selected toprovide an unbalanced transmission line having a predeterminedcharacteristic impedance at said mean wave length, said second sectionsof said inner and outer conductors having a relative spacing selected sothat said second section of said inner conductor and the other one ofsaid pair of conductive portions provide a balanced transmission linehaving approximately said predetermined characteristic impedance, saidloading means being so selected that said conductive portions of saidouter conductor provide a stub line having a characteristic impedanceless than that of an additional stub line formed by said second sectionof said inner conductor and said one conductive portion of said outerconductor and eflective substantially to compensate the impedancevariations of said balancedvcircuit arrangement and said additional stubline over said range of wave lengths.

15. A balanced-to-unbalanced circuit connector comprising, an outerconductor including a first section and a contiguous second sectionhaving av pair of longitudinal slots extending from one end of saidouter conductor and forming in said second section a pair of conductiveportions, an inner conductor including a first section and a contiguoussecond section coaxiaily supported within said first and second sectionsrespectively of said outer conductor and connected to one of saidconductive portions substantially at the free end thereof, said firstsections of saidinner and outer conductors having a relative spacingselected to provide an unbalanced transmission line having apredetermined characteristic impedance at a given operating wave length,said second section of said inner conductor and th other one of saidpair of conductive portions having a relative spacing selected toprovide a balanced transmission line having approximately saidpredetermined characteristic impedance, and said second section of saidinner conductor and said one conductive portion having a relativespacing selected to provide 'a stub line connected to but having asubstantially greater characteristic impedance than said balanced line.

HAROLD A. WHEEIER.

